Supercharged internal combustion engine

ABSTRACT

A supercharged internal combustion engine has a supercharger operable to selectively supply a mass of air from below through above atmospheric air pressure according to the operating requirements of the engine. The supercharger has a shuttle combined with a throttle valve that controls the mass of air directed to an air mass bypass opening and supplied to the internal combustion engine. The shuttle has rollers that ride on rails that allow the shuttle to move to open and close the air mass bypass opening in communication with a casing that directs a mass of atmospheric air and a bypass mass of air interfused with the mass of atmospheric air to an air mass inlet of the supercharger.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority of U.S. patent application Ser. No.62/249,874 filed Nov. 2, 2015.

FIELD OF THE INVENTION

The invention is in the technical art of superchargers for internalcombustion engines operable to supply air to the engines that rangesselectively from below through above atmospheric pressure conditionsaccording to the power requirements of the engines to increase fuelefficiency and performance of the engines.

BACKGROUND OF THE INVENTION

Air displacement devices are used to increase the supply of air and fuelto internal combustion engines to boost engine horsepower. An example ofan air displacement device is the “Roots blower” shown by P. H. Roots inU.S. Pat. No. 30,157 and G. Scheerer in U.S. Pat. No. 2,201,014. Each ofthese devices has a belt-driven shaft that drives two close-clearancerotors. The rotating rotors during each rotation sweep out a specificvolume of air to an air receiver, such as an internal combustion engine.The rotational speed of the rotors largely determines the unthrottledvolume of air discharged by the device to an air receiver.

C. N. Hansen and P. C. Cross in U.S. Pat. No. 6,241,498 disclose asupercharger having cooperating rotors drivably connected to an internalcombustion engine for delivering an air/fuel mixture to the combustionchamber of the engine. The rotors have semi-cylindrical pockets andprotrusions that continuously move air through the supercharger. Theunthrottled volume of air delivered by the supercharger depends on theoperating speed of the engine that drives the supercharger. Theunthrottled volume of air delivered by the supercharger operating at aconstant speed and pressure varies little. There are no air flowcontrols to regulate air flowing into and out of the supercharger.

C. N. Hansen and P. C. Cross in U.S. Pat. No. 8,539,769 disclose aninternal combustion engine combined with a variable displacementsupercharger operable to provide varying amounts of air to the enginethat range selectively from below through above atmospheric pressuresresponsive to the power requirements of the engine. The supercharger hasan air intake and male and female rotors rotated by the engine to move amass of air from the air intake to the engine. The rotors are locatedwithin a housing having an air bypass opening and an air bypass passagein communication with an air passage for directing bypass air to the airintake of the supercharger. A slide assembly is movably mounted on thesupercharger housing for movement toward the air intake of thesupercharger to change the position of the slide assembly along thelength of the rotor, the mass of air directed to the engine and the massof air flowing back to the air inlet of the supercharger. The slideassembly changes the position of the air bypass opening whereby more ofthe rotor lengths are effective to increase the mass of air aboveatmospheric pressure that is directed to the engine. A throttle valvelocated in the air inlet of the supercharger regulates the air massflowing into the supercharger below atmospheric pressure to control thepower of the engine when boost is not required. A control processor isused to regulate the positions of the slide assembly and throttle valveaccording to the power requirement of the engine.

T. D. Blackwell in U.S. Pat. No. 4,281,975 discloses a screw compressorwith male and female rotors and a slide valve mounted within acylindrical bore that intersects with the bores accommodating therotors. Air pressure exerted against the slide valve results in frictionand wear between the slide valve and adjacent structures. A cylindricalbore accommodates the slide valve. Anti-friction structures comprisingrollers rotatably mounted on the slide valve located in grooves in theside wall of the bore accommodating the slide valve. An alternativeanti-friction structure comprises transversely extended arcuate groovesin the surface of a cylindrical bore and anti-friction balls located inthe grooves in the bores and grooves in the slide valve.

L. S. Anderson in U.S. Pat. No. 6,227,834 discloses a screw compressorhaving male and female rotors and an adjustable slide for regulating gasdischarge pressure and capacity. The slide has opposite sides havinglongitudinal grooves. Rollers mounted on the side wall of the boreaccommodating the slide are located in the grooves of the slide toprevent the slide from being pressed into engagement with the rotors andto secure the slide against rotational movements. The supercharger ofthe invention has novel and advantageous structures and functions whichincrease the operating performance of an internal combustion engine.

SUMMARY OF THE INVENTION

The invention comprises a supercharged internal combustion engineaccommodating air that can range selectively from below through aboveatmospheric pressure according to the operating requirements of theengine. The internal combustion engine is generally a conventional4-stroke engine capable of using any number of combustible fuels. Thesupercharged internal combustion engine has increased fuel efficiencyover conventional internal combustion engines including turbo-chargedengines. The fuel efficiency of the supercharged internal combustionengine is related to the compression ratio in the combustion chambers ofthe engine. The supercharged internal combustion engine operates athigher and more efficient compression ratios because the density of theretained gas fraction in the combustion chamber is lower at the end ofthe exhaust stroke. Reduced in-cylinder temperatures at the beginning ofthe compression stroke help to prevent detonation of the air/fuelmixture and allows for higher compression ratios, which improves fuelefficiency. The supercharger has a shuttle combined with a throttlevalve operable to regulate varying amounts of a mass of air to thecombustion chambers of the engine that ranges selectively from belowatmospheric pressure to above atmospheric pressure according to thepower requirement of the engine. The supercharger produces the lowestparasite power losses by minimizing the air pumping work required tomeet the power requirement of the engine. The supercharger has a housingwith chambers or bores accommodating male and female helical rotors. Thehousing includes a bypass air passage allowing air to flow from thebores back to an air intake casing attached to the housing. The airintake casing has an air inlet passage in communication with one or moreair inlet openings to the bores accommodating the male and femalerotors. The air inlet passage of the casing aids the flow of air to theair inlet ends of the rotors and minimizes and reduces turbulence of airflow to the rotors. A throttle valve regulates the flow of atmosphericair into the air inlet passage of the air intake casing. The throttlevalve operates between nearly closed to open positions to regulate theamount of the mass of air below atmospheric pressure or near atmosphericpressure flowing to the air intake casing. When the throttle valve is inthe open position air is free to flow into the air intake casingallowing the supercharger to increase the pressure of the mass of airdischarged by the supercharger above atmospheric pressure. The air inletpassage of the air inlet casing is surrounded with a diverging diffusionbody or barrier separated from the casing wall with a peripheral spaceopen to the bypass passage and a peripheral air exit opening incommunication with the air inlet passage adjacent the air inlet to thechambers accommodating the rotors. The bypass air and inlet air flowingin the air inlet passages merges and interfuses with a minimum ofinterference resulting in a smooth flow of air through the air inletcasing to the chambers containing the rotors. A wall separates the borescontaining the rotors from a section of the bypass passage adjacent theair inlet casing. The wall prevents outward radial movement of airentering into the bores containing the rotors from the air inlet casingand enables full duration suction of air into the entrance or suctionsection of the supercharger resulting in improved inlet air volumetricefficiency. A pair of longitudinal rails located in the bypass passageprovide linear guides for a shuttle that moves to open and close theopening between a chamber containing a rotor and the bypass passage. Theshuttle moves to progressively increase or decrease the active length ofthe rotors to regulate the mass of air above atmospheric pressuredirected to the engine. Each rail has outside linear flat surfacesangularly located relative to each other. The rails are secured withfasteners to the housing. Alternatively, the rails can be integral withthe housing. Rollers rotatably mounted on the body of the shuttle rideon the outside linear surfaces of the rails during movement of theshuttle on the rails. A servo electric motor rotates a helical screwoperatively connected to the shuttle to move the shuttle along the railsto vary the mass of air directed to the combustion chambers of theengine according to the power requirement of the engine. A controllerresponsive to engine operator input functions to control the shuttlepositioning servo motor and throttle valve to regulate the mass of airsupplied to the engine and bypass air directed into the bypass passageand back into the air flowing into the supercharger.

DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram of a supercharged internal combustion engineconnected to a supercharger for supplying air to the engine;

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 showing theroller shuttle in a closed no air bypass position;

FIG. 4 is a sectional view taken along line 3-3 for FIG. 2 showing theroller shuttle in an open air bypass position;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 5;

FIG. 7 is an enlarged sectional view of a modification of FIG. 5 of theair inlet casing;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 1;

FIG. 9 is an enlarged sectional view taken along line 9-9 of FIG. 1;

FIG. 10 is an enlarged sectional view taken along line 10-10 of FIG. 1;

FIG. 11 is a perspective view of the shuttle, helical screw and powerunit operable to rotate the helical screw;

FIG. 12 is an enlarged top plan view of the shuttle of FIG. 11;

FIG. 13 is a front elevational view of FIG. 12;

FIG. 14 is an end elevational view of the right end of FIG. 12;

FIG. 15 is a sectional view taken along line 15-15 of FIG. 12;

FIG. 16 is an enlarged sectional view taken along line 16-16 of FIG. 11;

FIG. 17 is an enlarged perspective view of the air discharge end sectionof the supercharger of FIG. 1;

FIG. 18 is an enlarged sectional view of the shuttle and shuttle housingportion of FIG. 8;

FIG. 19 is an enlarged sectional view of a first modification of theshuttle and shuttle housing portion of FIG. 8;

FIG. 20 is an enlarged sectional view of a second modification of theshuttle and shuttle housing portion of FIG. 8;

FIG. 21 is an enlarged sectional view of a third modification of theshuttle and shuttle housing portion of FIG. 8;

FIG. 22 is an enlarged sectional view of a fourth modification of theshuttle and shuttle housing portion of FIG. 8; FIG. 23 is a perspectiveview of the semi-circular sleeve with rails shown in FIG. 22;

FIG. 24 is a top plan view of the shuttle shown in FIG. 21; and

FIG. 25 is a sectional view taken along line 25-25 of FIG. 24.

DESCRIPTION OF THE INVENTION

A supercharged internal combustion engine 10, shown in FIG. 1, isoperatively connected to a supercharger 11 operable to supply a mass ofair to the engine. Engine 10 is a conventional internal combustionengine having four cylinders 12, 13, 14 and 15 accommodating pistons(not shown) operable to rotate a drive shaft 16. Engines having anynumber of cylinders can be operatively connected to supercharger 11 tosupply a mass of air to the engines. Engine 10 has an air intakemanifold 17 having a manifold chamber in air communication withcylinders 12 to 15. The exhaust gases generated by engine 10 aredischarged through an exhaust manifold 18 into an exhaust gas treatmentdevice and atmosphere. Fuel, such as gasoline, is introduced intocylinders 12 to 15 with fuel injectors 19, 20, 21 and 22 connected to afuel pump 23. Spark igniters 24, 25, 26 and 27 associated with cylinders12 to 15 are operable to initiate ignition of the air/fuel mixture incylinders 12 to 15. Each igniter is wired to an electronic signalcontroller 28 operable to cause igniters 24 to 27 to generate electricsparks or arcs that cause the air/fuel mixture to burn in timesequences. Engine 10 includes internal combustion engines having intakemanifolds that operate below atmospheric air pressure and or aboveatmospheric air pressure. Drive shaft 16 can be coupled to a motorvehicle drive system, a pump, an electric generator or power operatedmachines.

Supercharger 11 has a power input drive shaft 29 connected to a powertransmitting apparatus 31 that drivably connects engine 10 tosupercharger 11. Engine 10 has a front drive shaft 32 connected to apulley or wheel 33. An endless belt 34 trained about pulley 33 transmitsengine power to a pulley 36 connected to supercharger drive shaft 29.The operating speed of supercharger 11 is directly related to theoperating speed of engine 10. Other power transmitting apparatusincluding a gear drive or chain can be used to drivably connect enginedrive shaft 32 to supercharger drive shaft 29. An electric motor can beused to rotate the rotors of the supercharger.

Supercharger 11 operates to regulate varying amounts of a mass of air tothe combustion chambers of cylinders 12 to 15 that ranges selectivelyfrom below atmospheric pressure to above atmospheric pressure accordingto the power requirement of engine 10. In use, supercharger 11 operateswith significantly less supercharger shaft power of a conventional screwsupercharger for conditions typically dominating the normal motorvehicle driving cycle. Lower parasitic power losses are achieved bysupercharger 11 by minimizing the air pumping work required to meet thecurrent power requirement of the engine. Supercharged engine 10 hasincreased fuel efficiency compared to existing positive displacementsupercharged engines and turbo-charged engines. The fuel efficiency ofengine 10 is closely related to the compression ratio in the combustionchambers of cylinders 12 to 15. Engine 10 operates at a higher and moreefficient compression ratio because the density of the retained gasfraction in the combustion chambers of cylinders 12 to 15 at the end ofthe exhaust stroke is lower than that of a turbocharged engine becauseof the exhaust back pressure difference. The temperature of the intakegas in the combustion chambers of cylinders 12 to 15 at the beginning ofthe compression stroke is lower which helps to prevent detonationthereby allowing for a higher compression ratio. The result is improvedfuel efficiency of engine 10.

Supercharger 11 has a main housing or body 37 with end members 38 and 39adjacent opposite ends of body 37. An air inlet housing or casing 41 isattached to end member 39 with fasteners 42, shown as bolts or rodsextended through end members 39 into threaded holes in body 37. Otherfastening structures can be used to assemble end members 38 and 39 andair inlet casing 41 to body 37. Air inlet housing or casing 41 has atubular extension 43 having an air inlet passage 44 as shown in FIGS. 1and 2.

A throttle device 46 connected to tubular extension 43 is operable toregulate varying amounts of a mass of air flowing into supercharger 11thereby regulating varying amounts of a mass of air to the combustionchambers of cylinders 12 to 15 that ranges selectively from belowatmospheric pressure to at or near atmospheric pressure according to thepower requirement of engine 10. Throttle valve device 46 includes atubular member 47 having a passage 48 in communication with passage 44.A disk throttle valve 49 is movably mounted on tubular member 47 formovement between open and nearly closed positions. An electric motordriven control unit 51 operatively connected to throttle valve 49controls the open, partly open and nearly closed positions of throttlevalve in response to signals generated by controller 28. An air filter52 attached to throttle valve device 46 cleans atmospheric air, shown byarrows 53, prior to flowing through passages 48 and 44 into supercharger11. Other types of airflow control valves can be used to control theflow of air into the supercharger 11.

Housing 37, as shown in FIGS. 8, 9 and 10, has a first cylindricalchamber or bore 54 open to a second cylindrical chamber or bore 56.Bores 54 and 56 have a common opening 57. The size of opening 57 canvary. Housing 37 also has a passage or space 58 with an arcuate opening59 open to cylindrical bore 54. This opening has an arc of 50 degreescentered on the axis of rotation of shaft 62 accommodating rotor 61. Thearcuate length opening can vary. Male rotor 61 has five helical grooves73 created by protrusions, lands or vanes 75 circumferentially spacedaround the outer perimeter of the rotor. Female rotor 63 has sixcircumferentially spaced helical pockets, chambers or grooves 74 whichmesh with vane 75 of male rotor 61. Each vane 75 has convex shapedoutside walls that are complementary to the shapes of the inside wallsof grooves 74 of female rotor 63. The sizes, numbers, shapes, helicalconfigurations, and extent of vanes 75 and grooves 74 can vary. As shownin FIG. 3, male rotor 61 is mounted on an axial shaft 62. Opposite endsof shaft 62 accommodate ball or roller bearings 66 and 67 retained onend members 38 and 39. Female rotor 63 is mounted on axial shaft 64.Bearings 68 and 69 support shaft 62 on end members 38 and 39. Shafts 62and 64 have parallel rotational axes. A drive gear 71 connected to shaft64 is in driving engagement with a driven gear 72 connected to shaft 62.Drive shaft 29 is connected to drive gear 71 whereby the internalcombustion engine 10 connected to shaft 29 with power transmittingapparatus 31, shown in FIG. 1, rotates rotors 61 and 63 in oppositecircumferential directions to move air through supercharger 11. As shownin FIG. 9, housing 37 has an air discharge or exit opening 76 open tobores 54 and 56 and a passage 77 in tubular member 78. Tubular member 78is joined to a base 79 secured with fasteners, shown as bolts, tohousing 37. The outer end of tubular member 78 is attached to anintercooler or heat exchanger 82 operable to reduce the temperature ofthe air flowing from supercharger 11 to an optional air mass flow sensor80 located in the throttle body 47. Air flow sensor 80 wired tocontroller 28 provides continuous electric signals to controller 28corresponding to the air flow and air mass conditions directed into airinlet of casing 41. Other methods and devices may be used to determineor infer air mass flow rate to air inlet of casing 41 utilizing inputsensors for intake manifold air temperatures, intake manifold airpressure, throttle position and engine speed, etc. An air pressuresensor 85 interposed between heat exchanger 82 and air intake manifold17 is wired to controller 28. Air pressure sensor 85 generates airpressure signals that are transmitted to controller 28 whichincorporates the air pressure signals in the program that controlssupercharger 11.

Returning to FIG. 4, air intake section 50 of chamber 54 is separatedwith an arcuate wall 83 from passage 58. Wall 83 extends from end member39 to an air bypass opening 84 between chamber 54 and passage 58. Wall83 has a concave inside surface 86 that conforms with the inside surfaceof wall 55 of housing 37 surrounding chamber 54. Wall 83 preventsoutward radial movement of air away from rotor 61 and minimizesturbulence of air flow during the suction of the air into supercharger11. Full duration suction of air in the intake suction section 50 ofchamber 54 improves air volumetric efficiency.

A shuttle 87 located in passage 58 moves along the length of passage 58to regulate the length or size of bypass opening 84. Shuttle 87 movesfrom a first no air flow position closing the bypass opening, as shownin FIG. 3, to a second air flow position to a maximum bypass opening, asshown in FIG. 4. Shuttle 87 also moves to intermediate positions betweenthe close and maximum open locations to trap or confine in the groovesof the rotors the mass of air moved by supercharger 11 according to theoperating requirement of internal combustion engine 10. Shuttle 87changes the size of air bypass opening 84 exposing more of the rotorlengths being effective to change the mass of air above atmosphericpressure that is directed to the engine. As shown in FIG. 11, anactuator shown as a helical screw 88 rotated with an electric servomotor 89 is operatively connected to shuttle 87 to move shuttle 87between the close, nearly closed and maximum open locations therebychange bypass opening 84 and the effective air trapping length of therotors. As shown in FIG. 1, electric servo motor 89 is wired tocontroller 28. An angle encoder 91 operatively connected to motor 89senses the rotation of screw 88 providing controller 28 with dataconcerning the location of shuttle 87 relative to air bypass opening 84.Controller 28 functions to generate signals which activate electricservo motor 89 to rotate screw 88 to change the location of shuttle 87relative to bypass opening 84 to regulate the mass of bypass air flowinginto passage 58. Shuttle 87 can be linearly moved along rails 143 and148 between an air flow open and partly open positions and no air flowclosed position relative to air bypass opening 84 with actuatorsincluding a linear motor, a solenoid, pneumatic cylinder, hydrauliccylinder and a diaphragm or bellows, etc.

An operator control sensor 92 coupled to foot pedal 93 is used toprovide controller 28 with operator demand electric signals responsiveto movement of foot pedal 93 by the operator of engine 10. When engine10 is operating at low power levels and more power is demanded,controller 28 instructs motor control unit 51 to further open throttlevalve 49 whereby more air flows into supercharger 11 and out ofsupercharger 11 to engine 10. When throttle valve 49 is wide open andthe operator demands more power by pressing foot pedal 93, controller 28then signals servo motor 89 to progressively move shuttle 87 to increasethe effective air trapping length of the rotors thereby increasing theamount of air delivered to engine 10 to increase its power output. Ifthe operator demands further increases in power and shuttle 87 is notyet at its maximum delivery position, controller 28 will continue toadvance the shuttle position to increase the quantity of air deliveredto engine 10 until a limiting condition is reach such as maximum enginespeed or the knock-limited engine intake manifold air pressure, shuttleposition, or mass airflow amount. Controller 28 can be pre-programmedwith known limit values of knock-limited engine intake manifold airpressure, shuttle position, or mass airflow amount for each enginespeed. If the operator demands more power and such limits have beenreached, controller 28 will signal the vehicle transmission to downshiftthe gear ratio to the drive wheels to allow operation at a higher enginespeed that will produce more power. Controller 28 continuously positionsthrottle valve 49 and/or shuttle 87 to the positions that provide therequired amount of air to meet the demanded power at all engine speedswithout exceeding the knock-limited intake manifold pressure of engine10.

Returning to FIGS. 4, 5, 6 and 7, bypass air passage 58 open to apassage 96 in air inlet casing 41 receives bypass air, shown by arrow94. Wall 55 and wall 83 direct air into passage 96 and peripheral space98 between air inlet casing 41 and a barrier or air entrainment guidemember 99. Member 99 has a tubular neck 101 telescoped into and attachedto tubular extension 43. Neck 101 is joined to a diverging diffusionbody 102 having an open end 103 spaced from the inner end 104 of airinlet casing 41. A plurality of bosses 106 secure body 102 to air inletcasing 41 and maintain the peripheral space 98 between air inlet casing41 and body 102. Bypass air 94 flows from passage 58 into passage 96 andperipheral space 98 around body 102. A peripheral column of bypass air,shown by arrows 107, merges and interfuses with atmospheric air, shownby arrows 45, before air enters the suction section 50 of bores 54 and56 accommodating rotors 61 and 63. The air flows of bypass air andatmospheric air are aligned and entrained in the same direction. Thebypass air, shown by arrows 107, has a minimum of interference with theflow of atmospheric air, shown by arrows 45, in supercharger 11. Asshown in FIG. 3, when shuttle 87 is in a location closing the air bypassopening 84 air does not flow in passages 58 and 96 and throughperipheral space 98 and into the suction section of supercharger 11. Allof the atmospheric air, shown by arrows 45, flows uninterrupted throughair inlet casing 41 into bores 54 and 56 of supercharger 11.

A modification of air inlet housing 41 and air diverter or member 102 isshown in FIG. 7. The structures of the air inlet housing shown in FIG. 7have the same reference numbers as FIG. 6 with a suffix A. Body 102A isjoined to housing extension 43A whereby air inlet housing 41A and body102A is a one-piece structure.

Shuttle 87, shown in FIGS. 11 to 15, has a carriage or body 108 attachedto a threaded member 109 with fasteners 111, such as bolts. Helicalscrew 88 is threaded into threaded member 109 whereby rotation ofhelical screw 88 in selected clockwise or counterclockwise directions,shown by arrows 112, linearly moves shuttle 87 in passage 58 to alterthe size of air bypass opening 84 to change the effective air trappinglength of the rotors, as shown in FIGS. 3 and 4. Body 108 has a centerlongitudinal hole 113 accommodating helical screw 88. Hole 113 extendsthrough the length of body 108 allowing body 108 to linearly moverelative to the length of helical screw 88. Body 108 includes a concavewall 114 having an arcuate configuration concentric with thecircumferential curvature of the peripheral edges of vanes 73 of rotor61. The forward face or end 116 of wall 114 is inclined in a forwarddirection at an angle of about 30 degrees relative to the longitudinalextent of wall 114. Other inclined angles can be used for the forwardend 116 of wall 114. The inclined end 116 is generally complementary tothe helical angle of the vanes of rotor 61 and facilitates the flow ofbypass air from rotor 61 into air bypass passage 58. Body 108 has a topsurface 117 with a longitudinal groove 118 extended along the length ofsurface 117. A spring beam 119 has a middle section 120 attached with afastener 121, shown as a bolt, to body 108. Middle section 120 of beam119 has side edges contacting the opposite edges of body 108 of groove118 to prevent turning or rotation of beam 119 on body 108. Beam 119 hasspring arms 122 and 123 joined to center section 120. Arms 122 and 123are equal in length and extend in opposite longitudinal directions fromcenter section 120. Upwardly extended cylindrical rollers 124 and 126are attached to the outer ends of arms 122 and 123. As shown in FIGS. 14and 15, body 108 has shoulders 127, 128 and 129. Cylindrical rollers 131and 132 are rotatably mounted on shoulder 127. The axes of rotation ofrollers 131 and 132 are 90 degrees from the axes of rotation of rollers124 and 126. The angular relationship between the axes of rotation ofrollers 124, 126 and 131, 132 can vary. Cylindrical rollers 133 and 134are rotatably mounted on shoulder 128. Cylindrical rollers 136 and 137are rotatably mounted on shoulder 129. The axes of rotation of rollers133 and 134 and rollers 136 and 137 are 90 degrees apart. Other angularrelationships between the axes of rotation of rollers 133, 134 and 136,137 can be used.

Rollers 124, 126, 131-134 and 136, 137 are the same size with continuousouter cylindrical surfaces. FIG. 16 shows roller 136 having an invertedcap-shaped casing 138 retained on a needle bearing 139 with a washer141. A bolt 142 extended through needle bearing 139 is threaded intoshoulder 127 of body 108. Other types of rollers can be used with body108 to rotatably support shuttle 87 in air bypass passage 58.

As shown in FIGS. 17 and 18, a pair of rails or tracks 143 and 148located in passage 58 cooperate with shuttle 87 for low frictionlinearly guiding shuttle 87 along rails 143 and 148 for rapid movementbetween the air bypass open and closed positions of shuttle 87.Fasteners 144 and 149 secure rails 143 and 148 to the inside wallsurrounding passage 58 of housing 37. Rails 143 and 148 arecircumferentially spaced 135 degrees from each other. Thecircumferential distance between rails 143 and 148 can vary. Rail 143has a linear flat first side surface 146 and a linear second flat sidesurface 147. Surfaces 146 and 147 extend the length of rail 143 and arein planes located 90 degrees from each other. Surfaces 146 and 147 canhave different angle relationships. Second rail 148 has a linear flatfirst side surface 151 and a linear flat second side surface 152.Surfaces 151 and 152 extend the length of rail 148 and are disposed 90degrees from each other. Other angular relationships between surfaces151 and 152 can be used. Rollers 124, 131, 126 and 132 ride on rail 143.Rollers 133, 136, 134 and 137 ride on rail 148. The rollers engagelinear surfaces 146, 147 and 151, 152 of rails 143 and 148 to locatewall 114 concentric with the cylindrical inside wall 40 of housing 37.The axes of rotation of rollers 124 and 131 are parallel to flatsurfaces 146 and 147 of rail 143. The axes of rotation of rollers 133and 136, shown in broken lines in FIG. 18, are parallel to flat surfaces151 and 152 of rail 148. The rollers have low friction contact withrails 143 and 148 which allows shuttle 87 to be rapidly moved with aminimum of force of servo motor 89.

Returning to FIGS. 12, 13 and 18, shuttle 87 is subjected to airpressure, shown by arrows 153 in FIG. 18, generated in chamber 54 by therotation of rotors 61 and 63. The air pressure on wall 114 of shuttle 87forces rollers 131 and 132 into contact with linear flat surface 147 ofrail 143. The air pressure on wall 114 also forces rollers 136 and 137into contact with linear flat surface 152 of rail 148. Rollers 131, 132on rail 143 and rollers 136, 137 on rail 148 prevent outward or radialmovement of shuttle 87 relative to housing 37 and rotor 61 and preventsturning or rotation of shuttle 87 in passage 58. Rollers 124 and 126 arebiased into contact with linear flat surface 146 of rail 143. Arms 122and 123 are flexed to retain rollers 124 and 126 in contact with linearflat surface 146 of rail 143. Spring beam 119 applies a biasing force onrollers 124 and 126 that compensates for transient pressure reversals,manufacturing tolerances and thermal growth differentials of housing 37and of shuttle 87.

A second embodiment 200 of shuttle 287, shown in FIG. 19, is located inair bypass passage 258 of housing 237. Rails 243 and 248 are secured tohousing 237 with fasteners 244 and 249. Rail 243 has inwardly converginglinear flat surfaces 246 and 247. Rollers 224 and 231 rotatably mountedon body 208 ride on surfaces 246 and 247. Rail 248 has inwardlyconverging linear flat surfaces 251 and 252. Rollers 233 and 236rotatably mounted on body 208 ride on surfaces 251 and 252. Shuttle 287is moved along rails 243 and 248 with a helical screw 288 driven by aservo electric motor. Screw 288 extends through an axial hole 213through body 208. The drive mechanism for shuttle 287 comprises ahelical screw, a nut and a servo electric motor assembly as shown inFIG. 11. Body 208 has a concave surface 214 closing the air bypassopening 284 between chamber 254 and air bypass passage 258. The oppositelinear side portions 209 and 210 have linear longitudinal groovesaccommodating linear seals 211 and 212. Seals 211 and 212 are elongatedplastic members. Other materials including metal and composite materialscan be used for seals 211 and 212. The outer surfaces of seals 211 and212 located in sliding contact with the inside surface 238 of housing237 prevent air from flowing from chamber 254 around shuttle 287 intobypass passage 258.

A third embodiment 300 of shuttle 387 and housing 337, shown in FIG. 20,illustrates rails 343 and 348 integral with housing 337. Rail 343 hasinward converging linear flat surfaces 346 and 347. Rail 348 has inwardconverging linear flat surfaces 351 and 352. Rollers 324 and 331rotatably mounted on body 308 of shuttle 387 ride on surfaces 346 and347 of rail 343 and rollers 333 and 336 ride on surfaces 351 and 352 ofrail 348 during movement of shuttle 387 in air bypass passage 358. Anelongated screw 388 driven by a servo electric motor moves shuttle 387along passage 358 between air bypass open and closed locations tocontrol the mass of air directed to the internal combustion engineaccording to the power requirements of the engine.

A fourth embodiment 400 of shuttle 487 and housing 437, shown in FIG.21, has shuttle 487 located in an air bypass passage 458. Shuttle 487has a body 408 with an axial hole 413 accommodating an elongated helicalscrew 488 driveably connected to a servo electric motor to move shuttle487 along bypass passage 458. Shuttle body 408 has linear shoulders 425,426, 427 and 428 rotatably supporting rollers 424, 431, 433 and 436.Rollers 424 and 431 ride on rail 443 and rollers 433 and 436 ride onrail 448 during movement of shuttle 487 along passage 458 between airbypass open and closed locations to control the mass of air directed tothe internal combustion engine according to the power requirements ofthe engine. As shown in FIGS. 24 and 25, shuttle 487 has additionalrollers 432 and 434 that ride on rail 443 and rollers 435 and 440 thatride on rail 448.

A fifth embodiment 500 of the shuttle and housing accommodating theshuttle, shown in FIGS. 22 and 23, has a shuttle 587 located in anelongated air passage 558 in a semi-cylindrical sleeve 560. Passage 558is an air bypass passage open to a rotor chamber and air inlet casing.Sleeve 560 has an inside semi-cylindrical surface 561. Rails 562 and 563projected inwardly from surface 561 into passage 558 arecircumferentially spaced 135 degrees from each other. Othercircumferential spacing between rails 562 and 563 can be used to supportshuttle 587 on sleeve 560. Rail 562 has inward converging flat linearsurfaces 565 and 566 extended along the length of sleeve 560. Rail 563has inward converging surfaces 567 and 568 extended along the length ofsleeve 560. As shown in FIG. 22, sleeve 560 is located within housing537. The outside wall of sleeve 560 is in surface contact with theinside wall 573. Fasteners 572, shown as bolts, threaded into holes 569and 571 secure sleeve 560 to housing 537. Rollers 524 and 531 rotatablymounted on shuttle body 508 ride on rail surfaces 567 and 568 androllers 533 and 536 ride on rail surfaces 565 and 566 during movement ofshuttle 587 along passage 558. Body 508 has an axial hole 513accommodating a helical screw 588. Screw 588 is operatively connected toa servo motor which rotates screw 588 causing shuttle 587 to move alongpassage 558. The drive mechanism for shuttle 587 comprises a helicalscrew, a nut, and a servo electric motor assembly, as shown in FIG. 11.

The supercharger has been shown and described with reference topreferred embodiments of the air intake casing and shuttle forcontrolling the mass of air directed to an internal combustion engine.Modifications of the supercharger, air mass flow controls, shuttle, andshuttle drive mechanisms can be made by persons skilled in the artwithout departing from the invention.

1. A supercharged internal combustion engine comprising: an internalcombustion engine having a combustion chamber for accommodating a massof air and fuel, a supercharger operable to supply the mass of air tothe combustion chamber of the engine according to the mass of airrequirements of the engine for a given power output of the engine, saidsupercharger including a housing having opposite first and second ends,a bore providing a first chamber and a second chamber, an air mass exitopening and an air mass bypass passage, said second chamber and air massbypass passage having a common air mass bypass opening for allowing airto flow from the second chamber into the air mass bypass passage, amember connected to the housing and the engine, said member having apassage open to the air mass exit opening to allow an air mass to flowfrom the supercharger to the internal combustion engine, a first endmember connected to the first end of the housing, said first end memberhaving an air mass inlet open to said first and second chambers, asecond end member connected to the second end of the housing, a firstrotor located in the first chamber rotatably mounted on the first andsecond end members, a second rotor located in the second chamberrotatably mounted on the first and second end members, said first andsecond rotors having cooperating helical vanes and grooves wherebyrotation of the rotors moves a mass of air through the first and secondchambers along the lengths of the first and second rotors from the airmass inlet to the air mass exit opening and air mass bypass opening, awall joined to the housing located adjacent the first end member and anair mass inet section of the second chamber, said wall extended from thefirst end member to the air mass bypass opening for preventing a mass ofair in the air mass inlet section of the second chamber from flowingoutwardly into the air mass bypass passage, an air inlet casingconnected to the first end member, said air inlet casing having anatmospheric air mass inlet and an air mass passage open to the first andsecond chambers to allow an atmospheric mass of air to flow through thecasing into the first and second chambers, an annular body connected tothe casing located within the casing, said body being positioned inwardof the casing providing an annular space between the casing and body,said air mass bypass passage of the housing being open to said annularspace whereby bypass air mass flows from the air mass bypass passageinto the space between the casing and body, said body having an annularair exit opening between the casing and body whereby the bypass mass ofair flows from the annular space between the casing and body andinterfuses with the atmospheric mass of air flowing through the casinginto the first and second chambers, a shuttle located in the air massbypass passage, rails located in the air mass bypass passage, said railsbeing joined to the housing and extended partly along the length of theair mass bypass passage, said shuttle having a movable body toselectively close and open the air mass bypass opening to control theair mass directed to the internal combustion engine and the air massflowing from the second chamber into the air mass bypass passage, aplurality of rollers rotatably mounted on the body engageable with therails to movably support the shuttle on the rails for movement along therails, a drive mechanism operatively connected to the body of theshuttle for moving the shuttle along the rails between open and closedpositions relative to the air mass bypass opening thereby controllingthe air mass supplied to the internal combustion engine and the air massflowing through the air mass bypass opening, an actuator operable tocontrol the drive mechanism to regulate the position of the shuttlerelative to the air mass bypass opening to control the air mass directedto the engine according to the power requirements of the engine, a powertransmission device drivably connecting the internal combustion engineto the rotors of the supercharger whereby the internal combustion engineoperates the supercharger, an apparatus for introducing fuel into theair in the combustion chamber of the supercharger corresponding to theratio of flow of air mass directed to the combustion chamber of theinternal combustion engine by the supercharger, and a controller forproviding command signals for operating the actuator for moving theshuttle between the open and closed positions relative to the air massbypass opening and to control the apparatus to regulate the amount ofand timing of the fuel introduced into the combustion chamber of theinternal combustion engine.
 2. The supercharged internal combustionengine of claim 1 including: a throttle valve assembly connected to theair inlet casing operable to control the flow of an atmospheric air massbelow atmospheric pressure to the air inlet casing and superchager. 3.The supercharged internal combustion engine of claim 1 including: atubular member connected to the air inlet casing having an air passageopen to the air inlet of the air inlet casing, a throttle valve locatedin the air passage movably mounted on the tubular member for movementbetween open and nearly closed positions to control the flow of air massbelow atmospheric pressure to the air inlet of the air inlet casing, anda control unit operatively connected to the throttle valve to regulatethe movement of the throttle valve between open and nearly closedpositions to control the flow of atmospheric air mass to the air inletof the air inlet casing, said controller being operatively connected tothe control unit to actuate the control unit to move the throttle valveselectively between open and nearly closed positions to control the flowof air mass below atmospheric pressure to the air inlet casing and firstand second chambers of the supercharger.
 4. The supercharged internalcombustion engine of claim 1 wherein: each of said rails includes linearfirst and second surfaces angularly disposed relative to each other, andsaid plurality of rollers being engageable with said first and secondsurfaces and moveable along said first and second surfaces duringmovement of the shuttle in the bypass passage.
 5. The superchargedinternal combustion engine of claim 1 wherein: each of said railsinclude first and second surfaces angularly disposed relative to eachother, and said plurality of rollers have first rollers engageable withthe first surfaces of said plurality of rollers and second rollersengageable with the second surfaces of said plurality of rollers.
 6. Thesupercharged internal combustion engine of claim 1 wherein: the railsare integral with said housing.
 7. The supercharged internal combustionengine of claim 1 including: fasteners cooperating with the rails andhousing for securing the rails to the housing.
 8. The superchargedinternal combustion engine of claim 1 wherein: the rails include alinear first rail attached to the housing located in the air mass bypasspassage, a linear second rail attached to the housing located parallelto the first rail in the air mass bypass passage, said plurality ofrollers on the body of the shuttle being engageable with the first andsecond rails for movement along the air mass bypass passage toselectively open and close the air mass bypass opening.
 9. Thesupercharged internal combustion engine of claim 8 wherein: the firstand second rails each include a linear first surface and a linear secondsurface angularly disposed relative to each other, and said plurality ofrollers having first rollers engageable with the first surface of eachrail and second rollers engageable with the second surface of each rail.10. The supercharged internal combustion engine of claim 1 wherein: theair mass bypass opening extends parallel to the first and second rotors.11. The supercharged internal combustion engine of claim 1 wherein: theactuator comprises a member having threads secured to the body of theshuttle, an elongated screw operatively engageable with the threads ofthe member, a motor drivably connected to the screw operable toselectively rotate the screw in opposite rotational directions therebyselectively moving the shuttle to open and close the air mass bypassopening and said motor being operably connected to the controllerwhereby the controller controls the operation of the motor.
 12. Thesupercharged internal combustion engine of claim 1 wherein: the body ofthe shuttle has a first end, a second end spaced from the first end, afirst wall and a concave curved wall opposite the first wall extendedfrom the first end to the second end of the body, said concave curvedwall having an arcuate configuration concentric with the circumferentialcurvature of the peripherial edge of the rotor adjacent the shuttle,said first wall having first, second and third shoulders, said pluralityof rollers comprising first rollers rotatably mounted on the firstshoulder, second rollers rotatably mounted on the body between the firstand second shoulders, said first and second rollers being engagable withone of the rails, said third rollers rotatably mounted on the secondshoulder, fourth rollers rotatably mounted on the third shoulder, andsaid third and fourth rollers being engageable with a rail spaced fromthe one of the rails.
 13. The supercharged internal combustion engine ofclaim 12 wherein: the first end of the body being inclined in adirection complementary to the helical angle of the rotor adjacent tothe shuttle.
 14. The supercharged internal combustion engine of claim 12wherein: the first rollers comprise a pair of rollers, the secondrollers comprise a pair of rollers, the third rollers comprise a pair ofrollers, and the fourth rollers comprise a pair of rollers.
 15. Thesupercharged internal combustion engine of claim 1 wherein: the body hasa central hole extended from the first end to the second end of the bodyfor accommodating a linear screw of the drive mechanism.
 16. Thesupercharged internal combustion engine of claim 15 including: a memberhaving a threaded opening accommodating the screw aligned with thecentral hole in the body, and a fastener securing the member to thesecond end of the body.
 17. The supercharged internal combustion engineof claim 1 wherein: the body of the shuttle has a first end, a secondend spaced from the first end, a first wall, and a concave curved wallopposite the first wall extended from the first end to the second end ofthe body, said concave curved wall having an arcuate configurationconcentric with the circumferential curvature of the peripheral edge ofthe rotor adjacent the shuttle, said first wall having a portion thereoflocated between the first and second shoulders, said portion having agroove extended from the first end to the second end of the body, aflexible member located in said groove, a fastener connecting theflexible member to the first wall of the body, first rollers rotatablymounted on the first shoulder, second rollers rotatably mounted on theflexible member, said flexible member biasing the first rollers andsecond rollers into engagement with one of the rails, third rollersrotatably mounted on the second shoulder, fourth rollers rotatablymounted on the third shoulder, and said third and fourth rollers beingengageable with a rail spaced from the one of the rails.
 18. Thesupercharged internal combustion engine of claim 17 wherein: the firstend of the body being inclined in a direction complementary to thehelical angle of the rotor adjacent to the shuttle.
 19. The superchargedinternal combustion engine of claim 17 wherein: the first rollerscomprise a pair of rollers, the second rollers comprise a pair ofrollers, the third rollers comprise a pair of rollers, and the fourthrollers comprise a pair of rollers.
 20. The supercharged internalcombustion engine of claim 17 wherein: the body has a central holeextended from the first end to the second end of the body foraccommodating a linear screw of the drive mechanism.
 21. Thesupercharged internal combustion engine of claim 20 including: a memberhaving a threaded opening accommodating the screw aligned with thecentral hole in the body end, and a fastener securing the member to thesecond end of the body.
 22. A supercharged internal combustion enginecomprising: an internal combustion engine having a combustion chamberfor accommodating a mass of air and fuel, a supercharger operable tosupply the mass of air to the combustion chamber of the engine accordingto the mass of air requirements of the engine for a given power outputof the engine, said supercharger including a housing having oppositefirst and second ends, a bore providing a first chamber and a secondchamber, an air mass exit opening and an air mass bypass passage, saidsecond chamber and air mass bypass passage having a common air massbypass opening for allowing air to flow from the second chamber into theair mass bypass passage, a member connected to the housing and theengine, said member having a passage open to the air mass exit openingto allow an air mass to flow from the supercharger to the internalcombustion engine, a first end member connected to the first end of thehousing, said first end member having an air mass inlet open to saidfirst and second chambers, a second end member connected to the secondend of the housing, a first rotor located in the first chamber rotatablymounted on the first and second end members, a second rotor located inthe second chamber rotatably mounted on the first and second endmembers, said first and second rotors having cooperating helical vanesand grooves whereby rotation of the rotors moves a mass of air throughthe first and second chambers along the lengths of the first and secondrotors from the air mass inlet to the air mass exit opening and air massbypass opening, a shuttle located in the air mass bypass passage, railslocated in the air mass bypass passage, said rails being joined to thehousing and extended partly along the length of the air mass bypasspassage, said shuttle having a movable body to selectively close andopen the air mass bypass opening to control the air mass directed to theinternal combustion engine and the air mass flowing from the firstchamber into the air mass bypass passage, a plurality of rollersrotatably mounted on the body engageable with the rails to movablysupport the shuttle on the rails for movement along the rails. a drivemechanism operatively connected to the body of the shuttle for movingthe shuttle along the rails between open and closed positions relativeto the air mass bypass opening thereby controlling the air mass suppliedto the internal combustion engine and the air mass flowing through theair mass bypass opening, an actuator operable to control the drivemechanism to regulate the position of the shuttle relative to the airmass bypass opening to control the air mass directed to the engineaccording to the power requirements of the engine, a power transmissiondevice driveably connecting the internal combustion engine to the rotorsof the supercharger whereby the internal combustion engine operates thesupercharger, an apparatus for introducing fluid into the air in thecombustion chamber of the supercharger corresponding to the rate of flowof air mass directed to the combustion chamber of the internalcombustion engine of the supercharger, and a controller for providingcommand signals for operating the actuator for moving the shuttlebetween the open and closed positions relative to the air mass bypassopening and to control the apparatus to regulate the amount and timingof the fuel introduced into the combustion chamber of the internalcombustion engine.
 23. The supercharged internal combustion engine ofclaim 22 including: a throttle valve assembly operatively associatedwith the air mass inlet of the first end member for controlling the flowof an atmospheric air mass below atmospheric pressure to the first andsecond chambers of the supercharger.
 24. The supercharged internalcombustion engine of claim 22 wherein: each of said rails includeslinear first and second surfaces angularly disposed relative to eachother, and said plurality of rollers being engageable with said firstand second surfaces and moveable along said first and second surfacesduring movement of the shuttle in the bypass passage.
 25. Thesupercharged internal combustion engine of claim 22 wherein: each ofsaid rails include first and second surfaces angularly disposed relativeto each other, and said plurality of rollers have first rollersengageable with the first surfaces of said plurality of rollers andsecond rollers engageable with the second surfaces of said plurality ofrollers.
 26. The supercharged internal combustion engine of claim 22wherein: the rails are integral with said housing.
 27. The superchargedinternal combustion engine of claim 22 including: fasteners cooperatingwith the rails and housing for securing the rails to the housing. 28.The supercharged internal combustion engine of claim 22 wherein: therails include a linear first rail attached to the housing located in theair mass bypass passage, a linear second rail attached to the housinglocated parallel to the first rail in the air mass bypass passage, saidplurality of rollers on the body of the shuttle being engageable withthe first and second rails for movement along the air mass bypasspassage to selectively open and close the air mass bypass opening. 29.The supercharged internal combustion engine of claim 28 wherein: thefirst and second rails each include a linear first surface and a linearsecond surface angularly disposed relative to each other, and saidplurality of rollers having first rollers engageable with the firstsurface of each rail and second rollers engageable with the secondsurface of each rail.
 30. The supercharged internal combustion engine ofclaim 22 wherein: the air mass bypass opening extends parallel to thefirst and second rotors.
 31. The supercharged internal combustion engineof claim 22 wherein: the actuator comprises a member having threadssecured to the body of the shuttle, an elongated screw operativelyengageable with the threads of the member, a motor drivably connected tothe screw operable to selectively rotate the screw in oppositerotational directions thereby selectively moving the shuttle to open andclose the air mass bypass opening and said motor being operablyconnected to the controller whereby the controller controls theoperation of the motor.
 32. The supercharged internal combustion engineof claim 22 wherein: the body of the shuttle has a first end, a secondend spaced from the first end, a first wall and a concave curved wallopposite the first wall extended from the first end to the second end ofthe body, said concave curved wall having an arcuate configurationconcentric with the circumferential curvature of the peripherial edge ofthe rotor adjacent the shuttle, said first wall having first, second andthird shoulders, said plurality of rollers comprising first rollersrotatably mounted on the first shoulder, second rollers rotatablymounted on the body between the first and second shoulders, said firstand second rollers being engagable with one of the rails, said thirdrollers rotatably mounted on the second shoulder, fourth rollersrotatably mounted on the third shoulder, and said third and fourthrollers being engageable with a rail spaced from the one of the rails.33. The supercharged internal combustion engine of claim 32 wherein: thefirst end of the body being inclined in a direction complementary to thehelical angle of the rotor adjacent to the shuttle.
 34. The superchargedinternal combustion engine of claim 32 wherein: the first rollerscomprise a pair of rollers, the second rollers comprise a pair ofrollers, the third rollers comprise a pair of rollers, and the fourthrollers comprise a pair of rollers.
 35. The supercharged internalcombustion engine of claim 22 wherein: the body has a central holeextended from the first end to the second end of the body foraccommodating a linear screw of the drive mechanism.
 36. Thesupercharged internal combustion engine of claim 35 including: a memberhaving a threaded opening accommodating the screw aligned with thecentral hole in the body, and a fastener securing the member to thesecond end of the body.
 37. The supercharged internal combustion engineof claim 22 wherein: the body of the shuttle has a first end, a secondend spaced from the first end, a first wall, and a concave curved wallopposite the first wall extended from the first end to the second end ofthe body, said concave curved wall having an arcuate configurationconcentric with the circumferential curvature of the peripheral edge ofthe rotor adjacent the shuttle, said first wall having a portion thereoflocated between the first and second shoulders, said portion having agroove extended from the first end to the second end of the body, aflexible member located in said groove, a fastener connecting theflexible member to the first wall of the body, first rollers rotatablymounted on the first shoulder, second rollers rotatably mounted on theflexible member, said flexible member biasing the first rollers andsecond rollers into engagement with one of the rails, third rollersrotatably mounted on the second shoulder, fourth rollers rotatablymounted on the third shoulder, and said third and fourth rollers beingengageable with a rail spaced from the one of the rails.
 38. Thesupercharged internal combustion engine of claim 37 wherein: the firstend of the body being inclined in a direction complementary to thehelical angle of the rotor adjacent to the shuttle.
 39. The superchargedinternal combustion engine of claim 37 wherein: the first rollerscomprise a pair of rollers, the second rollers comprise a pair ofrollers, the third rollers comprise a pair of rollers, and the fourthrollers comprise a pair of rollers.
 40. The supercharged internalcombustion engine of claim 37 wherein: the body has a central holeextended from the first end to the second end of the body foraccommodating a linear screw of the drive mechanism.
 41. Thesupercharged internal combustion engine of claim 40 including: a memberhaving a threaded opening accommodating the screw aligned with thecentral hole in the body end, and a fastener securing the member to thesecond end of the body.
 42. A supercharged internal combustion enginecomprsing: an internal combustion engine having a combustion chamber foraccommodating a mass of air and fuel, a supercharger operable to supplythe mass of air to the combustion chamber of the engine according to themass of air requirements of the engine for a given power output of theengine, said supercharger including a housing having opposite first andsecond ends, a bore providing a first chamber and a second chamber, anair mass exit opening and an air mass bypass passage, said secondchamber and air mass bypass passage having a common air mass bypassopening for allowing air to flow from the second chamber into the airmass bypass passage, a member connected to the housing and the engine,said member having a passage open to the air mass exit opening to allowan air mass to flow from the supercharger to the internal combustionengine, a first end member connected to the first end of the housing,said first end member having an air mass inlet open to said first andsecond chambers, a second end member connected to the second end of thehousing, a first rotor located in the first chamber rotatably mounted onthe first and second end members, a second rotor located in the secondchamber rotatably mounted on the first and second end members, saidfirst and second rotors having cooperating helical vanes and grooveswhereby rotation of the rotors moves a mass of air through the first andsecond chambers along the lengths of the first and second rotors fromthe air mass inlet to the air mass exit opening and air mass bypassopening, an air inlet casing connected to the first end member, said airinlet casing having an atmospheric air inlet and an air outlet open tothe first and second chambers to allow an atmospheric mass of air toflow through the casing into the first and second chambers, an annularbody connected to the casing located within the casing, said body beingpositioned inward of the casing providing an annular space between thecasing and body, said air mass bypass passage of the housing being opento said annular space whereby the bypass air mass flows from the airmass bypass passage into the space between the casing and body, saidbody having an annular air exit opening between the casing and bodywhereby the bypass mass of air flows from the annular space between thecasing and body and interfuses with the atmospheric mass of air flowingthrough the casing into the first and second chambers, a shuttle locatedin the air mass bypass passage and movable along the air mass bypasspassage between open and closed positions to selectively close and openthe air mass bypass opening to control the air mass directed to theinternal combustion engine and the bypass air mass flowing through theair mass bypass opening to the air mass bypass passage and annular spacebetween the casing and the body, a drive mechanism operatively connectedto the shuttle for moving the shuttle between the open and closedpositions relative to the air mass bypass opening thereby controllingthe air mass supplied to the internal combustion engine and the bypassair mass flowing through the air mass bypass opening and annular spacebetween the casing and the body, an actuator operable to control thedrive mechanism to regulate the position of the shuttle relative to theair mass bypass opening to control the air mass directed to the engineaccording to the power requirements of the engine, a power transmissiondevice drivably connecting the internal combustion engine to the rotorsof the supercharger whereby the internal combustion engine operates thesupercharger, an apparatus introducing fuel into the air in thecombustion chamber of the supercharger corresponding to the rate of flowof air mass directed to the combustion chamber of the internalcombustion engine by the supercharger, and a controller for providingcommand signals for operating the actuator for moving the shuttlebetween the open and closed positions relative to the air mass bypassopening and to control the apparatus to regulate the amount of and timeof the fuel introduced into the combustion chamber of the internalcombustion engine.
 43. The supercharged internal combustion engine ofclaim 42 wherein: the housing includes a wall located adjacent the firstend member and air mass inlet section of the second chamber, said wallextended from the first end member to the air mass bypass opening forpreventing a mass of air in the air mass inlet section of the secondchamber from flowing outwardly into the air mass bypass passage.
 44. Thesupercharged internal combustion engine of claim 42 including: a firstlinear rail attached to the housing and located in the air mass bypasspassage, a second linear rail attached to the housing and locatedparallel to the first linear rail in the air mass bypass passage, saidshuttle having a body and a plurality of rollers rotatably mounted onthe body engageable with the first and second rails to movably supportthe shuttle on the first and second rails for movement along the airmass bypass passage to selectively open and close the air mass bypassopening.
 45. The supercharged internal combustion engine of claim 44wherein: each of the first and second rails include first and secondlinear surfaces angularly disposed relative to each other, and theplurality of rollers have first rollers engageable with the first linearsurfaces of the first and second rails and second rollers engageablewith the second linear surfaces of the first and second rails.
 46. Thesupercharged internal combustion engine of claim 42 including: athrottle valve assembly connected to the air inlet casing operable tocontrol the flow of atmospheric air mass to the air inlet casing andsupercharger.
 47. A air compressor operable to generate a mass of aircomprising: a housing including a bore providing a pair of parallelchambers, an air mass inlet for allowing a mass of air to flow into thechambers, an air mass outlet for allowing a mass of air to flow out ofthe chambers, an air mass bypass passage open to a low air pressurelocation for allowing a bypass mass of air to flow out of the chambersto the low air pressure location, an air mass bypass opening incommunication with the air mass bypass passage and one of said chambers,a pair of screw rotors having parallel axes of rotation located in thechambers, members rotatably mounting the rotors on the housing forrotation to move a first mass of air from the air mass inlet to the airmass outlet and move a second mass of air to the air mass bypass passageand low air pressure location, a shuttle located in the air mass bypasspassage moveable parallel to the axes of the rotors relative to the airmass bypass opening for selectively opening, partly opening and closingthe air mass bypass opening to vary the second mass of air flowingthrough the air mass bypass opening to the low air pressure location andthe first mass of air discharged out of the air mass outlet of thehousing, a pair of rails located in the air mass bypass passage, saidpair of rails being joined to the housing and extended parallel to theaxes of rotation of the rotors, said shuttle having a body locatedadjacent one of the rotors adopted to be moved to selectively open andclose the air mass bypass opening to vary the first mass of airdischarged from the air mass outlet and the second air mass flowing tothe air mass bypass passage, a plurality of rollers rotatably mounted onthe body engageable with the pair of rails to support the shuttle on therails for movement along the pair of rails to selectively open and closethe air mass bypass opening to vary the flow of the first mass of air tothe air mass outlet and the second air mass flowing to the air massbypass passage, and an actuator operatively connected to the shuttle formoving the shuttle along the pair of rails to selectively open and closethe air mass bypass opening to the air mass bypass passage whereby whenthe air mass bypass opening is open or partly open the first air massflows through the open or partly open air mass bypass opening to the lowair pressure location and the second air mass flows through the air massoutlet of the housing and when the air mass bypass opening is closed allof the air mass flows through the air mass outlet of the housing. 48.The air compressor of claim 47 wherein: the pair of rails are integralwith said housing.
 49. The air compressor of claim 47 including:fasteners cooperating with the rails and housing for securing the railsto the housing.
 50. The air compressor of claim 47 wherein: each of therails includes a linear first surface and a linear second surfaceangularly disposed relative to each other located in the air mass bypasspassage, and said plurality of rollers having first rollers engageablewith the first surface of the rails and second rollers engageable withthe second surface of the rails.
 51. The air compressor of claim 47including: a casing connected to the housing for directing atmosphericand bypass masses of air to the air mass inlet of the housing, saidcasing having an air mass inlet passage and an air mass outlet passage,said air mass outlet passage being in communication with the air massinlet of the housing whereby the atmospheric mass of air flows throughthe air mass inlet passage and air mass outlet passage to the air massinlet of the housing, an annular body connected to the casing andlocated inwardly within the casing providing an annular space betweenthe casing and body, said air mass bypass passage being open to theannular space whereby the bypass air mass in the air mass bypass passageflows into the annular space, said annular body having an annular endlocated inwardly relative to the air mass outlet passage of the casing,and said annular end of the body being located inwardly of the casingproviding a bypass air mass discharge opening to allow the bypass airmass in the annular space between the casing and body to interfuse andflow with the atmospheric air mass to the air mass inlet of the housing.52. The air compressor of claim 47 including: a wall joined to thehousing located adjacent the air mass inlet and the one of said rotors,said wall being extended from the air mass inlet to the air mass bypassopening for preventing a mass of air from flowing into the air massbypass passage before the air mass flows through the air mass bypassopening to the low air pressure location.
 53. The air compressor ofclaim 47 wherein: the air mass bypass opening extends parallel to theaxes of rotation of the pair of rotors.
 54. The air compressor of claim47 wherein: the actuator comprises a member having threads secured tothe body of the shuttle, an enclosed screw operatively engageable withthe threads of the member, and a motor drivably connected to the screwoperable to selectively rotate the screw in opposite rotationaldirections thereby selectively move the shuttle to open and close theair mass bypass opening.
 55. An air compressor operable to generate amass of air comprising: a housing including a bore providing a pair ofparallel chambers, an air mass inlet for allowing a mass of air to flowinto the chambers, an air mass outlet for allowing a mass of air to flowout of the chambers, an air mass bypass passage open to a low airpressure located for allowing a bypass mass of air to flow out of thechambers to the low air pressure location, an air mass bypass opening incommunication with the air mass bypass passage and one of said chambers,a pair of screw rotors having parallel axes of rotation located in thechambers, members rotatably mounting the rotors on the housing forrotation to move a first mass of air from the air mass inlet to the airmass outlet and move a second mass of air to the air mass bypass passageand low air pressure location, a shuttle located in the air mass bypasspassage movable parallel to the axes of the rotors relative to the airmass bypass opening for selectively opening, partly opening and closingthe air mass bypass opening to vary the second mass of air flowingthrough the air mass bypass opening to the low air pressure location andthe first mass of air discharged out of the air mass outlet of thehousing, a casing connected to the housing for directing atmospheric andbypass masses of air to the air mass inlet of the housing, said casinghaving an air mass inlet passage and an air mass outlet passage, saidair mass outlet passage being in communication with the air mass inletof the housing whereby an atmospheric air mass flows through the airmass inlet passage and air mass outlet passage to the air mass inlet ofthe housing, an annular body connected to the casing and locatedinwardly within the casing providing an annular space between the casingand the body, said air mass bypass opening being open to the annularspace whereby the bypass air mass in the air mass bypass passage flowsinto the annular space, said casing and annular body having a bypass airmass discharge opening to allow the bypass air mass in the annular spacebetween the casing and body to interfuse and flow with the atmosphericair mass to the air mass inlet of the housing, and an actuatoroperatively connected to the shuttle for moving the shuttle in thebypass passage to selectively open and close the air mass bypass openingto the air mass bypass passage whereby when the air mass bypass openingis open or partly open a bypass air mass flows through the open orpartly open air mass bypass opening to the low air pressure location andan air mass flows through the air mass outlet of the housing and whenthe air mass bypass opening is closed all of the air mass flows throughthe air mass outlet of the housing.
 56. The air compressor of claim 55including: a wall joined to the housing located adjacent the air massinlet and the one of said rotors, said wall being extended from the airmass inlet to the air mass bypass opening for preventing a mass of airfrom flowing into the air mass bypass passage before the air mass flowsthrough the air mass bypass opening to the low air pressure location.57. The air compressor of claim 55 wherein: the air mass bypass openingextends parallel to the axes of rotation of the pair of rotors.
 58. Theair compressor of claim 55 wherein: the actuator comprises a memberhaving threads secured to the body of the shuttle, an enlongated screwoperatively engageable with the threads of the member, and a motordrivably connected to the screw operable to selectively rotate the screwin opposite rotational directions thereby selectively move the shuttleto open and close the air mass bypass opening.
 59. A shuttle for asupercharger comprising: a body having a first end, a second end spacedfrom the first end, first wall and a concave curved second wall oppositethe first wall extended from the first end to the second end of thebody, said first wall having first, second and third shoulders, firstrollers rotatably mounted on the first shoulder, second rollersrotatably mounted on the body between the first and second shoulders,third rollers rotatably mounted on the second shoulder, and fourthrollers rotatably mounted on the third shoulder.
 60. The shuttle ofclaim 59 wherein: said first end of the body being inclined between thefirst wall and second wall.
 61. The shuttle of claim 59 wherein: thefirst rollers comprise a pair of rollers, the second rollers comprise apair of rollers, the third rollers comprise a pair of rollers, and thefourth rollers comprise a pair of rollers.
 62. The shuttle of claim 59wherein: the body has a central hole extending from the first end to thesecond end of the body for accommodating a linear screw.
 63. The shuttleof claim 62 including: a member having a threaded opening aligned withthe central hole in the body, and a fastener securing the member to thesecond end of the body.
 64. A shuttle for a supercharger having helicalscrews operable to move a mass of air from a first location to a secondlocation comprising: a body having a first end and a second end spacedfrom the first end, a first wall and a concave curved second wallopposite the first wall extended from the first end to the second end ofthe body, said first wall having first, second and third shoulders, saidfirst wall having a portion thereof located between the first and secondshoulders, said portion having a groove extended from the first end tothe second end of the body, a flexible member located in said groove, afastener connecting the flexible member to the first wall of the body,first rollers rotatably mounted on the first shoulder, second rollersrotatably mounted on the flexible member, third rollers rotatablymounted on the second shoulder, and fourth rollers rotatably mounted onthe third shoulder.
 65. The shuttle of claim 64 wherein: said first endof the body being inclined between the first wall and second wall. 66.The shuttle of claim 64 wherein: the first rollers comprise a pair ofrollers, the second rollers comprise a pair of rollers, the thirdrollers comprise a pair of rollers, and the fourth rollers comprise apair of rollers.
 67. The shuttle of claim 64 wherein: the body has acentral hole extended from the first end to the second end of the bodyfor accommodating a linear screw.
 68. The shuttle of claim 67 including:a member having a threaded opening aligned with the central hole in thebody, and a fastener securing the member to the second end of the body.